Influence of resource abundance on use of tree-fall gaps by birds in an isolated woodlot.

Abstract:

Of 44 species represented by adequate sample sizes (n>5) in spring, 9 were significantly more common in gaps, 2 more common in forest understorey. Nine of 17 species were captured more often in gaps during fall. During spring, flycatchers, ground insectivores, foliage insectivores, and granivore-omnivores were captured more frequently in gaps. Flycatchers showed no difference in fall, but other trophic groups, including frugivores, were captured more frequently in gaps than in forest understory sites. Bark foragers showed no statistical preference for gaps or forest understory in spring or fall. Total species per net and total captures per net correlated positively with density of foliage in the lower canopy and negatively with density of upper canopy foliage in both spring and fall. Total species and captures correlated positively with insect abundance in spring and with fruit abundance in fall. Foliage insectivores correlated positively with low canopy foliage and insect abundance in both spring and fall. Captures of frugivores correlated with fruit abundance in fall. Data support the hypothesis that birds are attracted to tree-fall gaps because of higher resource abundance.-from Authors

Año de publicación:

1986

Keywords:

Fuente:

scopus